1. Field of the Invention
The present invention relates to a dot-impact type of printer, more particularly, for printing marks on the edge of printing paper, which prevents fracture of a wire of a printing head and can print the desired marks on the edge of printing paper without requiring a large-sizing of printer.
2. Description of the Related Art
FIG. 10 shows an example of printed matter on which markings are printed on the edge of printing paper. The printed matter in FIG. 10 is recognized as "instant lottery ticket." There is a paper 101 in a predetermined shape and size, on which predetermined numbers, etc. have been printed in advance in predetermined rows. Marks 103 are printed at predetermined positions, including those on the left edge of the paper 101.
When a person buys the instant lottery ticket as shown in FIG. 10, he may select arbitrary number among the numbers printed in a predetermined row, then marks the selected number by drawing any checking line or painting it out, etc. The thus number-marked paper 101 is inserted in a data reader (OCR). The OCR detects the marks 103 printed on the left edge of the paper 101, so that the number in each row marked by the buyer may be detected.
FIG. 11 shows another type of printed matter like above. This kind of paper is printed by a certain type of machine when drawing a lottery. For example, when a person buys the lottery by selecting arbitrary number, etc., a receipt 105 as shown in FIG. 11 is issued. The receipt 105 has marks 109 at the predetermined positions including those on the left edge of the receipt 105. These marks 109 specify the information selected by the buyer. The information is then confirmed by inserting the receipt 105 in the OCR, so that the result (win or lose) in the lottery may be discriminated.
However, the prior arts as above described have the following problems.
Firstly, when marks 103 or 109 are to be printed on the left edge of the paper 101 or the receipt 105, it is necessary to start moving the head from the further side of the left edge of the paper. Namely, the printing should be carried out by moving a printing head toward the right side, starting from the further side of the left edge of the paper 101 or the receipt 105. In such an operation, a wire of the printing head may be caught on the left edge of the paper 101 or the receipt 105, which result in fracture of the wire.
Secondly, there is a problem of large-sizing of printer. When the printing is to be carried out on the edge of the paper 101 or the receipt 105, it is necessary to extend the printing area in the lateral direction to allow the further starting position as above. Thus the width of the printer shall be enlarged, which results in the large-sizing of printer.
For detailed explanation, as for a carriage of the printing head which ordinarily makes reciprocating movement, there are reverse areas at both ends of the printing area, in which the carriage changes its moving direction (from the movement toward the left side, to that toward the left side, and vice versa), and such reverse areas are not included in the printing area. Namely, the printing is carried out only in the area excluding the reverse areas. Accordingly, if the edges of the paper 101 or the receipt 105 should be included in the printing area, the printing area shall naturally be enlarged, thus the width of the printer is enlarged, which results in the large-sizing of printer.